Suffix array spoj 694 Distinct substrings

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Test instructions: Given a string, find the number of different substrings

Analysis: We can know the length of the same prefix between suffixes, if all suffixes follow suffix (sa[0]), suffix (sa[1]), suffix (sa[2]), suffix (sa[n]) in the order of calculation, it is not difficult to find, For each new add-in suffix suffix (sa[k]), it will produce a new prefix of n-sa[k]+1. But there are height[k] and the prefix of the preceding string is the same. So suffix (sa[k]) will "contribute" out of n-sa[k]+1-height[k] a different substring. The answer to the original question is the summation.

This "contribution" does not overlap, because each time the addition is for the current is not the same substring.

#include <cstdio> #include <cstring> #include <algorithm>const int N = 1e3 + 5;int sa[n], rank[n], height[    N];int T[n], t2[n], C[n];char s[n];void da (char *s, int N, int m = n) {int i, p, *x = t, *y = t2;    for (i=0; i<m; ++i) c[i] = 0;    for (i=0; i<n; ++i) c[x[i]=s[i]]++;    for (I=1; i<m; ++i) c[i] + = c[i-1];    for (i=n-1; i>=0;-I.) sa[--c[x[i]] = i;        for (int. k=1; k<=n; k<<=1) {for (p=0, i=n-k; i<n; ++i) y[p++] = i;        for (i=0; i<n; ++i) if (Sa[i] >= k) y[p++] = sa[i]-K;        for (i=0; i<m; ++i) c[i] = 0;        for (i=0; i<n; ++i) c[x[y[i]]]++;        for (i=0; i<m; ++i) c[i] + = c[i-1];        for (i=n-1; i>=0;-i) sa[--c[x[y[i]] [] = y[i];        Std::swap (x, y); p = 1;        X[sa[0]] = 0;        for (I=1; i<n; ++i) {X[sa[i]] = (Y[sa[i-1]]==y[sa[i]] && y[sa[i-1]+k]==y[sa[i]+k]? p-1: p++);        } if (P >= N) break;    m = p; }}void calc_height (intn) {int I, k = 0;    for (i=0; i<n; ++i) rank[sa[i]] = i;        for (i=0; i<n; ++i) {if (k) k--;        Int j = Sa[rank[i]-1];        while (s[i+k] = = S[j+k]) k++;    Height[rank[i]] = k;    }}int N;int Main () {int T; scanf ("%d", &t);        while (t--) {scanf ("%s", s);        n = strlen (s);        n++;        Da (S, N);        Calc_height (n);        int ans = 0;        for (int i=0; i<n; ++i) {ans + n-sa[i]-1-height[i];    } printf ("%d\n", ans); } return 0;}

　　

Suffix array spoj 694 Distinct substrings